Hepcidin is a type of antibacterial peptide that has broad-spectrum bactericidal and bacteriostatic effect, and belongs to the defensive protein family. When hepcidin gene is translated in liver, it generates a type of early polypeptide first; then, after the signal peptide of the early polypeptide is removed by enzyme digestion, it forms a pro-hepcidin; and then the pro-hepcidin is transported into blood circulation, and finally is sheared by propeptide convertase to form a mature hepcidin.
Hepcidin is related with hereditary hemochromatosis, anemia, iron metabolism disorders, chronic kidney diseases, and inflammatory reactions, etc.; however, the diagnostic result of the above-mentioned diseases can't be derived from the detection result of hepcidin directly owing to the existence of influencing factors such as individual differences; instead, the diagnostic result needs to be judged comprehensively depending on other influencing factors. Accordingly, qualitative and/or quantitative detection of hepcidin can provide intermediate information for diagnosis of the above-mentioned diseases.
It is very important to develop a simple and quick method for detecting hepcidin qualitatively and/or quantitatively. However, hepcidin that is of clinical detection significance only has 25 amino acids and its immunogenicity is very low; therefore, it is very difficult to obtain the corresponding antibody; whereas, most existing antibody-based detection methods, when used for detection, can't distinguish pro-hepcidin and hepcidin. In addition, the existing mass-spectrometry-based method for detecting hepcidin is usually: treating the sample that is suspected as containing hepcidin (e.g., serum and/or plasma sample) by mass-spectrometric sample pre-treatment (e.g., chromatographic separation or enrichment with a nano chip, etc.), and followed by mass spectrometric detection, and determining whether the sample contains hepcidin or determining the content of hepcidin in the sample according to the mass spectrometric detection result. The existing mass-spectrometry-based method for detecting hepcidin has low sensitivity and poor accuracy, owing to the fact that the quality of the sample to be injected for mass-spectrometric detection is still poor though it has been treated by mass-spectrometric sample pre-treatment such as chromatographic separation or enrichment with a nano chip.